1. Field of the Invention
The present invention relates to small animal restraining devices for use in laboratories.
2. Prior Art
Many devices are known and used to immobilize small laboratory animals so that operations, dissections and the like may be performed thereupon. The most common devices are those which hold the entire animal in an immobile position. One such device is disclosed in U.S. Pat. No. 2,832,313. Wherein a series of elongated flexible fasteners are attached to the animal's legs. The head of the animal is held by means of a holder in which an incisor enters and is retained.
Less common are the devices which hold the animal and in particular its head under virtually no toleance for movement. These types of devices provide the means so that a cannula or needle can be inserted into the skull to hit an infinately small target with a high degree of accuracy. U.S. Pat. No. 3,542,030 discloses a device of this type. The primary means of holding the animal's head is a pair of earbars which enter the outer ears to make firm, mechanical contact with the osslus structure. These earbars can be adjusted with great precision. The earbars also provide means for guiding the insertion of a cannula to the animal's pituitary gland. Two nosebars, which are clamped across the animal's upper jaw, are fixed to a carriage which can be adjusted to move the head vertically with precision. Once this device is adjusted, it can be used on like animals having similar structural dimensions without further adjusting. In order to employ the device of this invention, however, the animal must be anesthetized. Further, the nature of the guide means limits the place in the animal's head into which the cannula may be inserted.